Method of forming sand molds.



J. A. RAI'HBONE.

METHOD 01 PORMING SAND MOLDS. APPLIUATION FILED 1330.9, 1905.

Patented Feb. 15, 1910.

3 SHEETS-*SHEET 1.

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J. A. RATHBONE. METHOD of FORMING SAND MoLDs.

APPLICATION FILED DBO. 9, 1905. l 949,49 Patented Feb. 15, 1910.

3 SHEETS-SHEET 2.

ANDREW s cri/mm cu, Punto-umoupnms wAsmNnmN n r` J. A. RATHBONE.

METHOD 0F FORMING SAND MOLDS.

APPLICATION FILED DBG. 9, 1905.

49,42, Patented Feb.15,1910.

.3 SHEETS-SHEET 3.

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ENFER@ VIATE PATENT @FFIQFI JOI-IN A. RAII-IBONE, 0F UTICA, NEIN YORK,ASSIGNOR T0 RATHBONE IVIOLDING MACHINE CO., OF DETROIT, MICHIGAN, ACORFOBJAIION 0F MICHIGAN.

'METHOD OF FORIVIING SAND MOLDS.

Specification of Letters Patent.

Patented Feb. 15, 1910.

To @ZZ whom it may concern.'

Be it known that I, J or-IN A. RA'rHBoNE, a citizen of the United Statesof America, residing at Utica, in the county of Oneida and State of NewYork, have invented certainnew and useful Improvements in Methods ofForming Sand Molds, of which the fol: lowing is a specification,reference being had therein to the accompanying drawings.

The invention consists in an improved method of forming sand molds,being more particularly designed for use in the formation of multiple orseries molds.

In the present state of the art, multiple or series molds have beenemployed for forming castings, the several mold cavities havingcomplementary faces formed in the sand contained within adjacent moldflasks said flasks being then assembled in series. So far as I am aware,however, this system has not been employed, excepting for comparativelysmall work and has not been used for cored work employing cores ofmaterial size.

It is the object of the present invention to provide means for firmlyanchoring the body of sand within the flask between the molding faces;and further to provide means for forming core supports within the bodyof sand, which are accurately posi-V tioned in relation to the moldingfaces. Thus, when the sections of the mold are assembled and the coresplaced within the mold cavities, the latter will be held in eX- actlypredetermined position.

In the drawings, Figure 1 is a vertical section through a mold flask,illustrating the method of compacting the sand to form the mold cavitiesand also showing one means of positioning the core supports; Fig. 2 is asimilar view illustrating a modification; Figs. 3 and 4 illustratedifferent forms of chaplets which may be employed for the core supports;Fig. 5 is a view simii lar to Fig. 1, showing a modification in themethod of forming a core support; Fig. 6 illustrates a mold formed inaccordance with Fig. 5; Fig. 7 is a similar view showing anothermodification; Fig. 8 is a perspective view of a chaplet support, such asshown in Fig. 7 and Fig. 9 illustrates a completed series mold.

In carrying out my improved method, I preferably employ a moldingmachine of any suitable construction which is adapted to compact thesand within the flask by the impact of the pattern.

As illustrated in Fig. l, A is the bed of the machine, upon which asuitable pattern face such as B is mounted and C is the mold flaskpositioned to surround the bed and pattern and resting upon a san'dframe D, which is yieldably supported, as by the springs E. F is anopposed pattern face which is secured to the movable plunger G, and H isa second sand frame above the flask C.

rIhe construction of the machine further than described is immaterial tothe present invention and is therefore not illustrated but it is to beunderstood that in operation, the loose sand fills the flask and the twosand frames, after which the descent of the plunger G will cause thecompression of the sand into the space inclosed by the flask, thesprings E yielding to permit the downward movement of the latter. Inthis operation it is, however, important that the plunger should descendwith sufficient velocity to throw the sand into all of the depressionsof the pattern face, which effect cannot be successfully produced merelyby pressure but requires an impact.

To sustain the body of sand between the mold faces, the flasks areprovided with bars or other anchors I projecting inward centrally fromtheir sides. These bars or anchors being in the center of the mass ofsand, do not interfere with the compacting of the latter but, when theoperation is completed, afford a strong support for the molded faces.Thus, these faces are firmly held against downward stress due to theweight of the molten metal, or upward stress due to flotation pressure,even where the mold cavities are of considerable size. Furthermore, whenthe mold sections are assembled in series, the intermediate sectionswill be as strong as the end sections, which is not the case where thesand is supported solely from the sides of the flask.

To sustain and accurately position the cores within the mold cavities,chaplets are necessary and the accuracy of the work depends upon theplacing of' these chaplets so that their inner ends will project anexactly predetermined distance within the mold cavity. Ordinary methdsof positioning the chaplets are not adapted to use where the sand iscompacted by impact of the pattern.

Thus, if a chaplet bearing of ordinary construction were placed withinthe mold flask, as, forrinstance, upon the bar I, it would form anobstruction to the movement of the sand during compression and wouldresult in the formation of a hard spot, preventing the opposed patternsfrom coming the required distance from each other and destroying theaccuracy of the work. rfhe hard spot in the sand also frequently causesthe mold to blow.7 I have avoided this difficulty by providing means foraccurately positioning the chaplets without interference with the flowof the sand and which may be accomplished in several different ways.

As illustrated in Fig. l, the chaplets are positioned during thecompression of the sand by providing guides J upon the cross bar I, withwhich the inner ends of the chaplets L may be engaged. The patterns arealso apertured in alinement with these guides, so as to permit the endof the chaplet to pass therethrough and into contact with a block orchair M, these blocks being secured respectively to the bed A andplunger Gr. The length of chaplets used is preferably slightly in excessof that required to project the proper distance into the mold cavity andthus, during the descent of the plunger, the blocks M will impingeagainst the ends of the chaplet before the end of the movement and willcause an upsetting or compression of the chaplet to reduce it to theproper length.

In Fig. 3, one form of compressible chaplet is shown, which is formed oftwo sections a b provided respectively with a socket c and an engagingshank 0l.

Another form is illustrated in Fig. el, in which, intermediate the endsof the chaplet, there is a laterally bent portion permitting ofcompression. These and various other forms of chaplet are adapted foruse with the method above described.

In Fig. 2, a modification is illustrated in which the chaplet L7 insteadof abutting against the bar I, extends completely through the body ofthe sand and is positioned by compression between the opposed blocks Mon the bed and plunger. IVith this latter' construction, the chapletmust be sustained by the body of the sand and to this end is providedwith a laterally projecting central anchor f.

Another modification is illustrated in Fig. 5, in which the opposedpatterns are provided with chaplet prints N N in alinement with eachother and which extend inward beyond the pattern face. During thecompression of the sand, these prints form a hard spot therebetweenwhich will afford a support for the chaplet. The chaplet L2, asillustrated in Fig. (i, is provided with a middle portion g and an endportion h,the latter being formed of baked sand and of a shape to fitthe cavity formed by the prints N N. Thus, these chaplets when placed inposition, will form with the baked sand portion 7L, the complementaryface of the mold cavity and, by reason of the wide bearing of saidportion /L which is supported upon the hard sand, the metallic chapletwill be held from displacement and in accurately predetermined position.

In Figs. 7 and 8, another modification is illustrated in which coresupporting bearings are formed directly upon the bar I, being eitherintegral therewith or formed of a separate piece rigidly attachedthereto. These bearings 0 are so formed that they will cut through thesand during the descent of the plunger and will therefore not interferewith the free flowing of the sand. As illustrated in Fig. 7, the chapletbearing is formed by tapering the end of the projecting member O, so asto form a knife-edge P, which, as illustrated, is in the shape of across. The tapering sides Q extending from the knife-edge, willlaterally deflect the sand but the sharpened edges will neverthelessafford a stable support for the base of the chaplet such as R.

In all of the various modifications above referred to, the core supportsare accurately positioned during the compacting of the sand so that thechaplets will extend a predetermined distance into the mold cavity andwill accurately position the core.

That I claim as my invention is l. The method of forming sand molds 300which consists in compacting sand within a flask between opposedpatterns to form opposite molding faces for adjacent mold cavities andin simultaneously positioning in predetermined relation and within thebody of the compacted sand, between said molding faces, a supportingmember.

2. The method of forming sand molds which consists in compacting sandwithin a flask between opposed patterns to form opposite molding facesfor adjacent mold cavities and in simultaneously positioning inpredetermined relation to said faces core supports.

3. The method of forming sand molds which consists in compacting sandwithin mold flask between opposed patterns to form the molding faces foradjacent mold cavities and in simultaneously positioning and anchoring achaplet within the sand so as to have a portion thereof projecting intothe mold cavity.

4. The method of forming sand molds which consists in compacting sandwithin a mold fiask between opposed patterns to form the molding facesfor adjacent mold cavities and in simultaneously positioning a chapletwithin the sand and in adjusting the length thereof by end compression.

5. The method of forming sand molds `which consists in compact-ing sandagainst a patterned face and in positioning a supporting member for amolding face other than that formed by the compacted sand by forcingsaid member through the sand.

6. The method of forming sand molds which consists in compacting sandagainst a patterned face and simultaneously forcing a supporting memberfor a molding face other than that formed by the compacted sand throughthe sand to position the same.

7. The method of forming sand molds which consists in relatively movinga flask and a pattern to compact sand in the flask againstthe pattern,and in simultaneously positioning a supporting member for a molding faceother than that formedv by the compacted sand.

8. The method of forming sand molds Which consists in relatively movinga flask and pattern to compact sand in the flask against said pattern,and simultaneously positioning and compressing endWise a core support.

In testimony whereof I alX my signature in presence of two Witnesses.

JOHN A. RATHBONE.

Witnesses:

JAMES P. BARRY, EDWARD D. AULT.

